For manufacturing an eyeglass lens, a commercially available circular lens (usually called as a blank lens) should be processed into an intended shape, for example, a shape in conformity with the configuration of an eyeglass frame. FIG. 1 is a view showing a process of processing a circular lens into an eyeglass lens using a grinder such as a diamond wheel. As shown in FIG. 1, the apparatus for processing eyeglass lens (lens edger) is equipped with a grinder 20 which is rotated by a motor 22, and a circular lens 10 fixed to a clamp 24 is positioned opposite to the grinder 20. The grinder 20 includes a rough-machining grinder wheel 20a, a bevel-machining grinder 20b, an incline-machining grinder 20c, a surface-finishing grinder 20d. The clamp 24 serves to rotate the lens 10 in the R direction and/or to move in Y direction. The apparatus for processing eyeglass lens moves the clamp 24 toward the rough-machining grinder 20a (Y direction in FIG. 1) until the periphery of the lens 10 comes into contacted with the rotating rough-machining grinder 20a, and then the periphery of the lens 10 is grinded. When this grinding and polishing process is performed over the entire periphery of the lens 10 by rotating the lens 10 in R direction (three-axis movement of the lens 10), the lens 10 can be roughly grinded and polished. In FIG. 1, a reference numeral 26 denotes a lens fixing tape, and a reference numeral 28 denotes a lens fixing block, which are used to firmly attach the lens 10 to the clamp 24.
After completing the rough-machining of the eyeglass lens 10 as described above, the lens 10 is fixed to an eyeglass frame, a lens fixing string, etc., and the side surface (edge) of the lens 10 is processed into a shape desired by the user. FIG. 2 is a view showing various shapes at the edge (side surface) of the eyeglass lens processed. As shown in FIG. 2, in order that the entire edge of the eyeglass lens 10 is inserted and fixed in the groove formed in the inside of the eyeglass frame, the edge of the eyeglass lens 10 is processed to have a mountain-shaped portion (∧) (A in FIG. 2, ‘bevel-processing’), a mountain-shaped portion and an inclined portion (FIG. 2B), or a flat portion and an inclined portion (FIG. 2C). The bevel-processing denoted by A in FIG. 2 is performed by the bevel-machining grinder 2b which has a groove formed in the circumference thereof (See FIG. 1). For example, the lens 10 roughly processed by the rough-machining grinder 20a is moved so as to be in contact with the bevel-machining grinder 20b. The edge of the lens 10 is polished by the bevel-machining grinder 20b so that a mountain-shaped portion may be formed at the edge of the lens 10. The mountain-shaped portion and an inclined portion shown in B of FIG. 2 can be formed by polishing the edge of the lens 10 with the incline-machining grinder 20c of asymmetric wheel after forming the mountain-shaped portion at the edge of the lens 10 with the bevel-machining grinder 20b (See FIG. 1). The flat portion and an incline portion shown in C of FIG. 2 can be formed by polishing the edge of the lens 10 with the incline-machining grinder 20c after flatting the edge of the lens 10 with the rough-machining grinder 20a. 
On the other hand, as shown in D of FIG. 2, the groove 82 (U-shaped) is also formed at the edge of the eyeglass lens 10 (‘grooving process’). In the semi-rimless eyeglasses, the lens fixing string or a part or the whole of the eyeglass frame of thin thickness is fitted into the groove 82 to fix the eyeglass lens 10, so that the grooving process is also called ‘semi-rimless process’. The ‘grooving process’ cannot be performed by the large-scale lens processing apparatus shown in FIG. 1, so it is performed by a separate small grinder for grooving (grooving device). FIG. 3 is a perspective view of a conventional grooving device which is additionally mounted onto the lens processing apparatus (see Korean Patent Unexamined-Publication No. 10-2006-0054560). As shown in FIG. 3, the grooving device 30 comprises a wheel 32 for forming a groove (groove-forming wheel) at the edge of the lens 10; a wheel shaft 34 for supporting the groove-forming wheel 32; a wheel-shaft-moving rotating member 36 whose one end is mounted on the wheel shaft 34 and the other end is rotatably mounted on a fixing block 38, for moving the wheel shaft 34; a wheel-moving motor 42 mounted on the fixing block 38, for moving the wheel-shaft-moving rotating member 36 via a worm gear 40; and a wheel-rotating motor 44 for rotating the groove-forming wheel 32 and the wheel shaft 34 at a high speed through a pulley and a belt mounted inside the wheel-shaft-moving rotating member 36. In operation, when the wheel-moving motor 42 is driven, the rotating force of the wheel-moving motor 42 is transmitted through the worm gear 40, to rotate the wheel-shaft-moving rotating member 36 in the direction of the arrow in FIG. 3 so that the groove-forming wheel 32 is moved to a polishing position. Next, the clamp 24 to which the lens 10 is fixed is moved to bring the groove-forming wheel 32 into contact with the edge of the lens 10 and then the groove-forming wheel 32 is rotated, so that a groove 82 having a desired depth is formed in the edge of the lens 10. Thus, the ‘grooving process’ is performed by the grooving device 30 which is a small grinder with small curvature.
Recently, in accordance with varieties of consumer demands and glasses use, the eyeglass frames and eyeglass lenses having various shapes and curvatures are used. The eyeglasses with special shapes are made for demanding sports or design rather than vision correction (for example, glasses for goggles). Among the eyeglasses with special shapes, there is a case where the conventional processing apparatus may not be able to process the periphery or edge of the eyeglass lens so as to be suitable for the shape of the eyeglass frame. For example, in the case where only a part of the eyeglass lens is irregularly inserted into the eyeglass frame, it is sometimes difficult to precisely process the periphery of the eyeglass lens only by moving the lens in three axes. Alternatively, when the step-processing and bevel-processing are required on the front and rear edge surfaces of the high curve lens of 6 or more curve, the processing axis of the processing apparatus, for example, the wheel shaft 34 should tilt or move freely along the curve of the lens. Therefore, in the processing the lens having edge of such a complicated shape, used is a large-scale processing apparatus (a device for a lab) which is capable of freely moving a grinding device and a wheel shaft. Further, in order to precisely process the edge surface of the eyeglass lens into a step shape, a tool with a small area for polishing must be used, so that a long time is required for processing, and in order to improve the workability, the roughness of the surface to be grinded must be lowered.